Greg Kroah-Hartman has put the slides and a transcript to his keynote at OLS online. The title speaks volumes: "Myths, Lies, and Truths about the Linux kernel". He starts off: "I'm going to discuss the a number of different lies that people always say about the kernel and try to debunk them; go over a few truths that aren't commonly known, and discuss some myths that I hear repeated a lot."

>I've been kind of arguing both ways (stable API vs non stable API), and now I'm thoroughly convinced that a non-stable API is the absolute best way to go for kernel development.

Surely it makes easier to do kernel development (in a bad way, though). But it makes impossible to scale out driver development. So as a result, you have a limited set of drivers and no vendors. As it is already told multiple times.

The kernel development and driver development are different tasks with different skills. There is a small set of experts who can make good work on kernel and there are huge set of hardware designers who can develop drivers for their hardware.